Transition Metals and Nanoparticles

Question 1

Transition Metals Properties

Answer 1

• Relatively high melting point
• Relatively high density
• Relatively high strength
• Relatively high hardness
• React very slowly

Question 2

Transition Metals as Catylists

Answer 2

Very useful catalysts - they speed up reactions without being used up - ability of transition metals to adopt multiple oxidation states, form complexes, and form strong bonds with other atoms makes them highly effective catalysts.

Question 3

Transition Metals as Coloured Compounds

Answer 3

When transition metals form compounds, they take on a distinct colour. For instance, cobalt(III) sulfate is red.

Question 4

Charges and Ions: Transition Metals

Answer 4

NAUGHTY CHILDREN
They do not behave regularly and are spontaneously charged - thus they can form many differently charged ions. Copper for instance, can form Cu+ OR Cu2+ ions.

In compounds the charge is automatically given in brackets roman numerals.

Question 5

Nanoscience is concerned with…

Answer 5

tiny things

Question 6

Nanoparticles may have properties that are _____________ from those for the same materials in bulk

Answer 6

different

Question 7

Nanoparticles have different properties from those of the same material in bulk because they have a high surface area to

Answer 7

volume ratio.

Question 8

Nanoparticles: a high percentage of their atoms are _________ at their surface

Answer 8

exposed

Question 9

Nanoparticles are not very/very reactive?

Answer 9

Very: As surface area per volume increases, materials can become more reactive. A simple

Question 10

The use of nanoparticles should mean that smaller quantities of materials are needed - much more reactive, yet much smaller than materials with normal size particles. This is a more __________ approach however there are some concerns about their _____________ impact.

Answer 10

sustainable; environmental

Question 11

Some uses of nanoparticulate materials:

Answer 11

1. Sunscreen
   metal oxides are used in sunscreens for protection from the sun. nanoparticles of the metal oxides can be coated with silica which can be adjusted at an atomic level thus they became more effective at blocking the sun’s rays.
2. Cosmetics
   nanoparticles are absorbed deeper into the skin so are more effective in cosmetics such as deodorants and moisturisers.
3. Glass can be coated with titanium oxide nanoparticles. Sunshine triggers a chemical reaction that breaks down dirt that lands on the window. When it rains, the water washes off the broken down dirt.

Question 12

Nanotubes

Answer 12

Carbon nanotubes are hollow tubes made of rolled-up graphene sheets (a single layer of carbon atoms)

Question 13

the increased use of nanoparticles needs more research into possible issues that might arise in terms of health and the environment:

Answer 13

Nanoparticles when inhaled or easily entering the blood stream can have unpredictable effects on our cells.

Could find their way into the atmosphere - air pollution.

Could impact aquatic life as there are metallic nanoparticles in clothing.

Question 14

Use of nanotubes

Answer 14

Like graphene, nanotubes are strong and conduct electricity because they have delocalised electrons. These properties make nanotubes useful for nanotechnology, electronics and specialised materials.